Welllll ... that depends.
Established canon dictates that if your character is pretty new (historically speaking) then you'd probably be serving the NSE.
Of course, there's nothing
stopping your character from serving Yamatai. You should probably ask where your character could best be used.
Tom is the Poobah of Nepleslia. He tends to be a busy guy, so leaving a PM and a YIM message is recommended.
Yangfan runs the Celia. You should definitely PM him if you want to join, as he can only handle so many players.
Wes runs the Sakura. Ask him or his moderator,
Kotori.
Sgzyr and
Sypher are your mods for the Mikomi.
Zakalwe is in charge of the Valiant. Remember, that's the British plotship, so your timezone might work out well for it.
Interested in less-than-ethical dealings? PM
Rine or
Porcelain Doll as "Dirty Dealings" has many different plots.
And, of course, there's the 5th Expeditionary, operated chiefly by
Venquia and
Rei. Your plot moderators are the lovely
Lin and me (
Doshii Jun).